1. Field of the Invention
This invention relates to a sewing apparatus and, more particularly, to a sewing apparatus having a milling drill for grooving a slot in a cassette, which holds work to be sewed, in accordance with a sewing pattern.
2. Description of Related Art
A sewing apparatus of that type is known, for instance, as shown in FIG. 7. As shown in FIG. 7, a sewing apparatus 1 comprises a table 2, a sewing machine 3 disposed on the table 2, and an X-Y moving unit 4 disposed on the same. This X-Y moving apparatus 4 moves a cassette 5 which holds work to be sewed in X and Y directions relative to the sewing machine 3, whereby the work is sewed into a predetermined pattern. As shown in FIG. 8, the cassette 5 includes, for example, a holding plate 6 for holding work and a fixing plate 7 for fixing the holding plate 6 to the X-Y moving unit 4 of the sewing apparatus 1. A slot 8 corresponding to a sewing pattern is grooved in the holding plate 6. This slot 8 is grooved using a milling unit 9 attached to the top part 3a of the sewing apparatus 1 before actually sewing the work.
This milling unit 9 includes a milling drill 10 and a vertical driving mechanism (not shown) for vertically moving the milling drill 10, and an end mill 10a for grooving purposes which is fixedly inserted into the lower end of the milling drill 10. The rotation, interruption, and vertical movement of the milling drill 10 are effected as a result of operation of a drill rotation/stop switch and a drill up/down switch provided on a control panel 11 by an operator.
To groove a slot, the milling drill 10 is moved downwardly so as to make the tip end of the end mill 10a create a hole at a predetermined location (a processing start position) of the cassette 5. Thereafter, the start switch of the control panel 11 is turned on to actuate the X-Y moving unit 4, so that the cassette 5 is moved in the X and Y directions. As a result, the grooving of a slot for one sewing pattern is automatically carried out. At this time, the X-Y moving unit 4 moves the cassette 5 based on sewing data which the sewing machine 3 utilizes to sew the work.
If the slot is grooved based on sewing data for one sewing pattern that includes the repetition of sewing action and feeding action for feeding the cassette without stitching action of a needle, the milling drill 10 is stopped and moved upwards by operating the drill rotation/stop switch and the drill up/down switch on the control panel 11 after the slot for the beginning of the sewing pattern (for example, area A shown in FIG. 6) has been grooved. Then, a feed switch (not shown) on the control panel 11 is turned on to actuate the X-Y moving table 4, whereby the cassette 5 is fed over a predetermined distance to the next sewing start position (for example, position P shown in FIG. 6). The feeding action of the X-Y moving unit 4 at this time is carried out based on feeding data included in the sewing data.
The milling drill 10 moves downwards and then rotates as a result of the operation of the drill rotation/stop switch and the drill up/down switch on the control panel 11 by the operator. Accordingly, a hole is formed at the machining start position on the cassette 5. The start switch on the control panel 11 is then turned on, so that the X-Y moving unit 4 is actuated to move the cassette 5 in accordance with the sewing pattern. In this way, the grooving of the cassette 5 for the next portion of the sewing pattern (for example, area B shown in FIG. 6) is automatically effected.
A plurality of slots 8 are grooved in the cassette 5, as shown for example in FIG. 6, through the repetition of the above mentioned operations.
However, in the case of sewing pattern data that include repetition of sewing action and feeding action, it is necessary for the operator to operate the switches on the control panel 11 in order to downwardly move and rotate the milling drill 10 and start the feeding action of the X-Y moving apparatus 4 every time a slot for an area to be sewed is grooved. Further, every time the cassette is fed after the slot for one pattern has been grooved, it is necessary for the operator to operate the switches on the control panel 11 so as to stop and move the milling drill 10 upwards and start the feeding action of the X-Y moving unit 4. In this way, the grooving of the slot based on the above mentioned sewing pattern data involves frequent switching action, which results in a physical burden on the operator.